As with all fields of modern commerce, agricultural production increasingly places a premium on efficient use of resources and productivity of investment. Mechanical advancements in plowing, seeding, and harvesting machinery have for decades contributed to increasing yields of plant crops. Although the active employment of similar productivity enhancing technology in animal crops has trailed plant culture automation, such advancements are now spreading to meat producers.
The culture of pigs for slaughter has particularly demanding economics. In order to maximize the crop of piglets, a producer seeks to have as few boar for the number of fertile sows as possible. A boar is capable of producing on average sufficient semen to artificially inseminate 15 sows twice a week, although a boar is only capable of inseminating two sows a week through mating. In a traditional practice, the sows to be inseminated are aligned for service by a boar, and are inseminated twice. Because a litter of as many as 12 piglets is desirable, it is important that each sow receive sufficient semen. Hence, in practice, a pork producer must retain many more boar than is optimal. Furthermore, the actual coupling of the boar with the sows requires additional labor for supervision which adds to the overall cost of the pigs produced.
Artificial insemination (AI) technology has made it possible to collect semen from a boar without contact with the sow, and to then inseminate each sow with a controlled and tested quantity of semen in an isolated environment. With modern AI techniques, a 1,000 sow herd can be adequately handled with only three to four boars.
The economic benefits of AI are well recognized. Nevertheless, the biological processes involved place demanding burdens on the practitioners. Unlike plant culture, in which seeds and seedlings are naturally adapted to survive in inclement weather and dirty conditions, AI products must be collected, treated, and transported under hygienic conditions and at controlled temperatures.
The collection of the boar semen itself is at present far from automated. An agricultural worker must lead the boar into the collection area and induce the animal to mount a simulated sow or collection dummy. Once ejaculation begins, the worker positions a plastic bag, retained in an insulated mug, to receive the ejaculate. Because only a single worker is involved, one hand manipulates the boar's penis to ejaculate into the mug, while the other hand maneuvers the mug to receive the biological material. The collection is further complicated by the fact that fluids present on the prepuce of the boar's penis are toxic to the semen. Hence it is important that they not contaminate the collected semen.
Because the boar ejaculate contains a gel plug fraction, it is necessary to filter this more viscous fraction from the semen. In conventional collection practices, a sheet of filter paper or gauze material was positioned over the opening to the mug and held in place with a rubber band. The operation of positioning and securing the filter required some manual dexterity and skill, and presented many opportunities for contamination of the semen both during collection and during separation of the filter from the collection bag.
What is needed is a boar semen collection bag which is easier to install in the collection mug, and which is conducive to hygienic collection practices to facilitate collection of semen of optimum quality.